This application is a further development of the subject matter of my prior application Ser. No. 549,633 filed Feb. 13, 1975, now U.S. Pat. No. 3,995,734. One of the problems faced by the prior art manure pumping systems is the bridging of straw or other livestock bedding in the hopper which supplies the animal waste to the pumping chamber. The manure and straw are typically delivered to the hopper by a conventional barn cleaner having a chain with flights which travel a circuit through a barn gutter to sweep or push the manure from the gutter to the manure pump hopper. When bridging occurs, the manure is not removed from the hopper and accumulates at the hopper as the barn cleaner chain continues to deliver manure to the hopper. The spill-over at the hopper then requires manual feed of the manure into the hopper until the bridging is overcome. The present invention provides a hopper construction and apparatus to minimize straw bridging and facilitate feed of material from the hopper into the pumping chamber.